1. Field of the Invention
The present invention relates generally to the fields of bio-potential sensory measurements and transmission thereof for medical diagnostic purposes, and in a specific though non-limiting embodiment, to a comfortable, easily-affixable, portable bioelectric interface used to detect, monitor and communicate data relating to a subject patient's ECG waveform characteristics.
2. Description of the Related Art
Although well-known for over a century, the full benefit of the diagnosis of electrocardiogram recordings has not been realized, primarily because it has not yet been brought to the state of full clinical exploitation such technology deserves. Possible reasons for this shortfall include institutional resistance to sophisticated new electronics capable of subsuming the functions of many previously existent devices; misperceptions within the medical community regarding the possible uses of such systems when the technology is fully matured; the fact that few, if any, prototypical devices have been reduced to practice for experimentation, etc.
The net result of such reluctances has been to restrict the proliferation and effectiveness of ECG monitoring systems to clinics, hospitals, and emergency rooms. More effective functionality, such as auto-detection, wireless transmission, and ultimate ease of usage, has heretofore been unknown.
For example, the state of the art presently is to affix upon a subject an electrocardiogram recording system based on measurement of the potential difference from at least a pair of electrodes that are distinctly separated, and which connect with leads that terminate in the amplification stage. Examples of standard lead systems include the signal averaging x, y, z Frank set, and the 10 electrode averaging systems derived from the well-known, clinically standard 12 lead system. In virtually all cases, the electrodes are connected with wire leads to either an amplifier or a recording device.
It is problematic, however, that when affixing subjects with the standard 12-lead monitoring system, subjects must be affixed with all of the electrodes disposed in a proper anatomical position. Failure to so equip the subject results in either failure or poor reporting of the apparent ECG waveform.
Even when proper anatomical disposition is achieved, orientation and grouping of disjunctive constituent clusters is adversely influenced by the orientation of the myocardium muscle fibers with respect to the aspect of the cumulatively resulting solid angle obtained from a set of the electrodes. With respect to the sequence of activation, the spread of the activation stimulus moves from endocrinal sites on out to the transmural space. This space is heavily affected by the anisotrophic properties of the ventricular muscle.
It is intuitive that excitation or the wavefront will spread more rapidly along the long axes of the cardiac cell than in the transverse direction. In ventricular walls, fibers are oriented roughly parallel to both endocardial and epicardial surfaces, however there are some transverse connections between cells, therefore the spread from one endocardial point may be viewed as oblique. This means there is a predominant axial spread along the length of the fiber with a lesser degree of spread or activation along the transverse in the perpendicular direction. The cumulative effects of the resulting cardiac field manifest into corresponding deviations in the measured cumulative waveform. In short, measuring errors translate into analytical errors, which are then compounded during the amplification and recording process. The net result is that a testing protocol designed to be exacting and precise is not, much to the detriment of cardiac patients and their attending physicians.
It is also problematic that the wire leads associated with the electrodes more or less requires that the subject be confined and remains relatively still, and the lack of reliable remote reporting capability ensures that the subject must remain on-site during cardio interrogation. Consequently, benefits that could otherwise have been derived from the remote acquisition, transmission, and interpretation of waveform characteristics are not realized.
Several derivative electrode arrangements (for example, large patches) have been proposed as an alternative to the clinical standard. However, the basic challenge remains that such electrodes must be contiguous and sufficiently spatially separated. To avoid that fundamental necessity, prior arts have attempted and demonstrated embedded wires disposed in a lamination in various arrangements. However, the obstacle remains that these electrodes are contained within a relatively larger patch in which electrodes still have to be connected by wires disposed at relatively large spatial distances.
Accordingly, the prior art is deficient in achieving a clinically useful diagnostic potential gradient from a single electrode comprising a plurality of sub-clusters subtending and delimiting an area of no more than a few of inches or less.
Logical protocols, functional depictions, and satisfactory methodologies (i.e., decision rules) for constructing waveforms obtained from two or three sets of selected sub-clusters disposed in specific orientations, whether contiguous or disjointed, and grouping strategies for determining optimum signal acquisition, are also conspicuously absent.